The thing is, I don't really game that much at all. A couple of nights a week I game a few hours, I rarely play more than 10 hours a week. The exception is the weeks after a big game is released that I really wanna play all day long like Skyrim. Also, a lot of the games on the list I haven't even played, I just bought when they were on the sale, cause I like them and might wanna play them in the future like Quake+DOOM, that's 15 games right there. The good thing with a big collection like this is that I am never bored.
I've also been on Steam since 2004. That's a long ass time and many games and sales ago.